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251.
Interactions of alcohols with soy protein isolate were investigated using an equilibrium dialysis method. It was found that interactions may involve hydrophobic association and, to some degree, hydrogen bonding. Studies with soy protein with various levels of denaturation indicated that denaturation of the protein by heating may limit its ability for the formation of hydrogen bonds with alcohols. The proteins under investigation exhibited practically unlimited binding capacity for alcohols.  相似文献   
252.
二氧化碳合成碳酸二甲酯催化剂的研究进展   总被引:1,自引:0,他引:1  
碳酸二甲酯是一种用途广泛的环境友好有机介成中间体,利用CO2合成碳酸二甲酯能有效利用C02资源,在环境保护和绿色合成化学方面具有重要的意义.综述了利用CO2合成碳酸二甲酯有机金属催化剂、氧化物催化剂、碱催化剂、负载型金属催化剂、醋酸盐催化剂及催化反应机理的研究进展,并展望了未来的发展方向.  相似文献   
253.
Experimental investigation of friction coefficient in tube hydroforming   总被引:2,自引:0,他引:2  
The friction coefficient between tube and die in guide zone of tube hydroforming was obtained. In hydroforming, the tube is expanded by an internal pressure against the tool wall. By pushing the tube through tool, a friction force at the contact surface between the tube and the tool occurs. In guiding zone, the friction coefficients between tube and die can be estimated from the measured axial feeding forces. In expansion zone, the friction coefficients between tube and die can be evaluated from the measured geometries of expanded tubes and FE analysis.  相似文献   
254.
The effect of microwave and conventional cooking methods, designed to simulate those used in home meal preparation, upon nutrient retention in Colossus Peas (Vigna uniguiculata) was studied. Neither method resulted in significant changes in the fat, protein, β-carotene and ascorbic acid content of the peas. Microwave cooking resulted in significantly greater losses of several ammo acids, but resulted in significantly greater retention of thiamin and riboflavin than the conventional treatment. Although each of the mineral components exhibited different magnitudes of loss by the two cooking methods, different due to method of cooking were not significant. Both Fe and Cu were completely retained in the peas cooked by both methods. Both cooking methods (15-60 min cooking) resulted in 92-97% loss of trypsin inhibitor.  相似文献   
255.
Isolates from fermented foods were screened for antimicrobial activity against gram‐negative bacteria. The most active isolate was identified as a Lactobacillus curvatus by biochemical analysis and ribotyping, and the isolate was designated as OSY‐HJC6. Lactobacillus curvatus OSY‐HJC6 was further tested for intracellular and extracellular production of antimicrobial agents. A reduction of > 8 log10 cfu/mL was observed when cell suspensions of Salmonella enterica serovar Enteritidis and Escherichia coli O157:H7 were treated with equal volumes of Lb. curvatus culture supernatant. Gram‐positive bacteria were not sensitive to the culture supernatant, but antimicrobial activity was detected when the cell extract was tested against several gram‐positive and gram‐negative bacteria. Culture supernatant and cell extract retained the antimicrobial activity after heating at 60–100C for 10 min but not after protease treatment. The cell extract of Lb. curvatus retarded the growth of E. coli p220 in broth medium and food extracts (i.e., bacteriostatic action) but showed bactericidal activity against the bacterium in phosphate buffer.  相似文献   
256.
Egg yolk powder was partly defatted using hexane, 95% ethanol, isopropanol, chloroform-methanol (2:1, v:v) hexane-isopropanol (77:23, w:w) and hexane-ethanol (77:23, w:w). Hexane-isopropanol was most efficient, extracting more than 50% of the lipid. Protein solubility and emulsifying activity of the extracted powder decreased after extraction. Hexane-isopropanol reduced emulsifying activity about 14% and protein solubility to 13.8% from 15.7%. Extraction with other solvents resulted in up to 41% loss of emulsifying activity; protein solubility decreased to as low as 3%. Ovalbumin in the water-soluble fraction of extracted egg yolk powder reduced its emulsifying effectiveness.  相似文献   
257.
GROWTH OF SALMONELLA AT LOW pH   总被引:6,自引:0,他引:6  
  相似文献   
258.
计及FACTS装置的概率特征根分析   总被引:4,自引:1,他引:4  
概率特征根分析计及了较宽范围的系统运行方式变化,利用柔性交流输电系统FACTS(Flexible AC Transmission System)装置上的附加控制器可以改善系统的动态特性,将现有的概率特征根分析扩展到包含FACTS功能模块。以并联型静态无功补偿器SVC(Static Var Compensator)和串联型可控串联补偿器TCSC(Thyristor-Controlled Series Capacitor)为例,在原有概率特征根模型的基础上,依据具体的元件模型和控制器表达,确定了形成系统状态空间方程时的相应线性化表达式;详细讨论了功能增加后系统状态方程矩阵的形成;通过补充相关的灵敏度计算,完成了计及FACTS装置的电力系统多运行方式下的小干扰稳定性分析。最后,在一个八机系统上进行了试算。在选定的附加控制器参数下,比较了增加SVC前后的系统主导特征根的变化,考察了附加控制器增益变化对临界特征根的影响。  相似文献   
259.
The human following becomes one of the significant procedure in human-friendly navigation of mobile robots.Many potential applications of human-following technology are developed lately.This paper sugg...  相似文献   
260.
An improved combined fine-coarse mesh (CFCM) method for two transmission line models of diffusion is described. The method allows regular cells of different sizes to be connected and solved simultaneously. The CFCM method is applied to (a) a finite difference algorithm, (b) a conventional transmission line model and (c) a lossy transmission line model. The latter model is shown to be the most accurate. The proposed CFCM method is also compared with the graded mesh and the multigrid techniques.  相似文献   
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